Steam generating device and washing machine having the same

ABSTRACT

A steam generating device, in which steam is generated just after the supply of water is performed so that the steam is supplied to a tub in a short time and the consumption of energy is decreased, and a washing machine having the same. The steam generating device includes a main body provided with a steam supply channel formed therein; a heater buried in the main body for heating the main body to heat water flowing along the steam supply channel; and a water supply control valve installed at an inlet of the steam supply channel.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority from Korean Patent Application Nos. 2004-90036, 2004-90037, filed Nov. 5, 2004, and 2004-94772, filed Nov. 18, 2004, in the Korean Intellectual Property Office, the disclosures of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a steam generating device and a washing machine having the same and, more particularly, to a steam generating device for supplying steam to the inside of a tub of a washing machine, and a washing machine having the same.

2. Description of the Related Art

Korean Patent Laid-open Publication No. 10-2004-85507 (dated Oct. 8, 2004) discloses a steam jet-type drum washing machine for jetting steam to the inside of a tub to increase a washing force.

A steam generating device of the washing machine disclosed by the above patent comprises a pressure container provided with an inlet for receiving washing water and an outlet for discharging steam, a heater installed in the pressure container for heating the washing water supplied to the inside of the pressure container, an inlet valve for adjusting the supply of the washing water to the inside of the pressure container, and an outlet valve for adjusting the discharge of the steam from the pressure container. The steam generating device further comprises a water level sensor for sensing the amount of the washing water supplied to the pressure container, a temperature sensor for controlling the operation of the heater according to the temperature in the pressure container, a pressure sensor for sensing the pressure in the pressure container, and an automatic temperature switch for cutting off power supplied to the heater when the temperature in the pressure container is excessively increased.

Since the above steam generating device is heated by the heater to generate steam under the condition that the pressure container is filled with water, the supply of the steam is delayed due to the time taken to heat the water in the pressure container. Accordingly, the steam generating device is disadvantageous in that the overall washing time is lengthened and energy consumption is high.

Further, the above steam generating device comprises the pressure container, the water level sensor, and the pressure sensor, thus having high production costs. Moreover, when the pressure in the pressure container is excessively increased due to a malfunction of the sensors, the pressure container is cracked and steam of a high temperature is leaked to the outside through the cracks of the pressure container.

SUMMARY OF THE INVENTION

Therefore, one aspect of the invention is to provide a steam generating device, in which steam is generated just after the supply of water is performed so that the steam is supplied to a tub in a short time and the consumption of energy is decreased, and a washing machine having the same.

A further aspect of the invention is to provide a steam generating device, which does not require components, such as a pressure container, a water level sensor, and a pressure sensor so as to greatly reduce the volume and the production costs thereof are decreased, and a washing machine having the same.

Another aspect of the invention is to provide a steam generating device, in which an outlet for discharging steam is opened at all times so as to prevent the increase in pressure thereof, and a washing machine having the same.

Yet another aspect of the invention is to provide a steam generating device which prevents the generation of scales therein, and a washing machine having the same.

In accordance with one aspect, the present invention provides a steam generating device comprising: a main body provided with a steam supply channel formed therein; a heater buried in the main body for heating the main body to heat water flowing along the steam supply channel; and a water supply control valve installed at an inlet of the steam supply channel.

The main body may be a metal mold manufactured under the condition that a pipe for forming the steam supply channel and the heater are buried in the main body.

Further, the steam supply channel may be formed in the longitudinal direction of the main body, and the heater buried in the main body is separated from the steam supply channel and extended in the longitudinal direction of the main body.

The inner diameter of an outlet of the steam supply channel may be smaller than the inner diameter of an inlet of the steam supply channel.

Further, a spiral coil member for delaying the flow of water may be installed in the steam supply channel.

The steam generating device may further comprise an overheating prevention device for controlling power applied to the heater when the heater is overheated.

The overheating prevention device includes a temperature sensor for sensing the temperature of the main body; and an automatic temperature switch for cutting off power applied to the heater when the temperature of the main body is raised more than a first predetermined temperature.

The overheating prevention device further includes a fuse for cutting off the power applied to the heater when the temperature of the main body is raised more than a second predetermined temperature higher than the first predetermined temperature.

The main body may be a metal mold manufactured under the condition that a core for forming the steam supply channel and the heater are buried in the main body.

Further, preferably, but not necessarily, an outlet of the steam supply channel is opened at all times.

The steam generating device may further comprise a control unit for controlling operations of the water supply control valve and the heater.

Moreover, the steam generating device may further comprise a noncohesive coating layer formed on the inner surface of the steam supply channel for preventing the generation of scales in the steam supply channel.

In accordance with another aspect, the present invention provides a washing machine having a steam generating device for supplying steam to the inside of a tub, the steam generating device comprising: a main body provided with a steam supply channel formed therein; a heater buried in the main body for heating the main body to heat water flowing along the steam supply channel; and a water supply control valve installed at an inlet of the steam supply channel.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects and advantages of the invention will become apparent and more readily appreciated from the following description of the exemplary embodiments, taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a sectional view of a washing machine consistent with the present invention;

FIG. 2 is a perspective view of a steam generating device of the washing machine in accordance with one embodiment of the present invention;

FIG. 3 is a sectional view of the steam generating device of the washing machine in accordance with one embodiment of the present invention;

FIG. 4 is a sectional view of a steam generating device of the washing machine in accordance with another embodiment of the present invention;

FIG. 5 is a circuit diagram illustrating the connection of an automatic temperature switch and a fuse of the steam generating device of the washing machine of the present invention; and

FIG. 6 is a sectional view of a noncohesive coating layer formed on the inner surface of a steam generation channel of the steam generating device of the washing machine of the present invention.

DETAILED DESCRIPTION OF THE ILLUSTRATIVE, NON-LIMITING EMBODIMENTS OF THE INVENTION

Reference will now be made in detail to the illustrative, non-limiting embodiments of the present invention, an example of which is illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. The exemplary embodiments are described below to explain the present invention by referring to the accompanying drawings.

As shown in FIG. 1, a washing machine in accordance with the present invention comprises a tub 11 having a drum shape installed in a main body 10 for containing washing water, and a rotary drum 12 rotatably installed in the tub 11.

The tub 11 slopes toward the installation ground of the washing machine at a designated angle (α) so that a front surface of the tub 11, through which an opening 11 a is formed, is located at a position higher than that of a rear surface of the tub 11. The rotary drum 12 installed in the tub 11 has the same structure as that of the tub 11. That is, a rotary central line A of the rotary drum 12 meets the installation ground of the washing machine at the designated angle (α) such that a front surface of the rotary drum 12, through which an opening 12 a is formed, slantedly ascends forward. Since a rotary shaft 13 connected to the central portion of the rear surface of the rotary drum 12 is rotatably supported by the central portion of the rear surface of the tub 11, the rotary drum 12 is rotated in the tub 11. A plurality of through-holes 12 b for circulating the washing water therethrough are formed through the cylindrical surface of the rotary drum 12, and a plurality of lifters 14 for lifting and dropping laundry when the rotary drum 12 is rotated are installed on the inner surface of the rotary drum 12.

A motor 15 for rotating the rotary shaft 13 connected to the rotary drum 12 is installed on the rear surface of the tub 11. The motor 15 includes a stator 15 a fixed to the rear surface of the tub 11, a rotor 15 b rotatably disposed outside the stator 15 a, and a rotary plate 15 c connecting the rotor 15 b and the rotary shaft 13.

An opening 16 is formed through the front surface of the main body 10 at a position corresponding to the opening 12 a of the rotary drum 12 and the opening 11 a of the tub 11 so that the laundry is inserted into or taken out of the rotary drum 12 through the opening 16, and a door 17 for opening and closing the opening 16 is installed at the opening 16.

A detergent supply device 18 for supplying detergent to the inside of the tub 11 and a steam generating device 30 for supplying steam to the inside of the tub 11 are installed above the tub 11. A drainage device 19 including a drainage pipe 19 a, a drainage valve 19 b and a drainage pump 19 c for discharging water in the tub 11 is installed below the tub 11.

The detergent supply device 18 includes a space for containing the detergent, and is installed in the front surface of the main body 10 so that a user can easily place the detergent inside the detergent supply device 18. A first water supply pipe 21 branched from a pipe connected to an external water supply source is connected to the detergent supply device 18, and a first water supply control valve 22 for controlling the supply of water to the detergent supply device 18 is installed in the first water supply pipe 21. A connection pipe 23 is installed between the detergent supply device 18 and the tub 11 so that the water, after passing through the detergent supply device 18, is supplied to the tub 11. The above structure causes the water supplied from the outside to pass through the detergent supply device 18 and then to be supplied to the tub 11, thereby causing the detergent in the detergent supply device 18, which dissolves in water, to be supplied to the tub 11.

A second water supply pipe 24 branched from the pipe connected to the external water supply source is connected to the steam generating device 30, and a second water supply control valve 25 for controlling the supply of water to the steam generating device 30 is installed in the second water supply pipe 24. Further, a steam supply pipe 26 for guiding the steam generated from the steam generating device 30 to the inside of the tub 11 is connected to the steam generating device 30.

As shown in FIGS. 2 and 3, the steam generating device 30 includes a main body 31 made of, for example, a metal molded by aluminum die-casting, a steam supply channel 32 installed in the main body 31 and provided with an inlet connected to the second water supply pipe 24 and an outlet connected to the steam supply pipe 26, a heater 33 buried in the main body 31 for heating water passed through the steam supply channel 32 to generate steam, and a temperature sensor 34 installed on the outer surface of the main body 31 for sensing the temperature of the main body 31 to control the heater 33.

The main body 31 of the steam generating device 30 is manufactured such that a pipe 35 for forming the steam supply channel 32 during the molding of the main body 31 by aluminum die-casting and the heater 33 are buried in the main body 31 as shown in FIGS. 2 and 3, or a core (not shown) for forming the steam supply channel 32 and the heater 33 are buried in the main body 31 as shown in FIG. 4. In FIG. 4, the steam supply channel 32 is formed in the main body 31 by eliminating the core after the molding of the main body 31 is completed.

In the above configuration, in which the main body 31 of the steam generating device 30 is made of a metal having an excellent thermal transfer property and the heater 33 is buried in the main body 31, water in the steam supply channel 32 is heated and changed to steam when water flows along the steam supply channel 32 under the condition that the main body 31 is heated to a high temperature by the heater 33. That is, since a small quantity of water is supplied to the steam supply channel 32 under the condition that the main body 31 is heated to the high temperature, the water is heated when the water passes through the steam supply channel 32, thus being changed to steam of a high temperature. In order to achieve the above process, preferably, but not necessarily, as shown in FIG. 2, the main body 31 has a rod shape having a designated length, the steam supply channel 32 is formed in the longitudinal direction of the main body 31, and the heater 33 buried in the main body 31 is extended in the longitudinal direction of the main body 31 under the condition that the heater 33 is separated from the steam supply channel 32. In this embodiment, as shown in FIG. 2, a U-shaped heater buried in the main body 31 is used as the heater 33.

As shown in FIG. 3, an outlet of the steam supply channel 32 of the steam generating device 30, which is connected to the steam supply pipe 26, is opened at all times, and the inner diameter (d1) of the outlet of the steam supply channel 32 is smaller than the inner diameter (d2) of an inlet of the steam supply channel 32. The above difference of inner diameters of the steam supply channel 32 generates channel resistance at the outlet and lengthens the time when steam is retained in the steam supply channel 32, thereby facilitating the generation of the steam of a high temperature. The above opened state of the outlet of the steam supply channel 32 prevents the excessive increase in pressure in the steam supply channel 32, thus facilitating the stable use of the steam generating device 30. As shown in FIGS. 3 and 4, a spiral coil member 37 for delaying the flow of water in the steam supply channel 32 to facilitate the generation of steam is installed in the steam supply channel 32.

A small quantity of water is supplied such that the supply of water and the suspension of water supply are repeated by the control of the second water supply control valve 25 or a small degree of the steam supply channel 32 is opened such that a small quantity of water flows in the steam generating device 30, thereby causing the water supplied to the steam generating device 30 to be heated to a steam state when the water passes through the steam supply channel 32. For this reason, preferably, but not necessarily, the second water supply control valve 25 employs an electric valve which is electrically opened and closed, or a flow control valve which controls the flow rate of fluid.

Although not shown in the drawings, a control unit for controlling the operations of the heater 33 of the steam generating device 30 and the second water supply control valve 25 is installed. The control unit controls the state (i.e., opened/closed state) or the opening degree of the second water supply control valve 25 using a predetermined program, thereby controlling the supply of water to the steam generating device 30. Otherwise, the control unit controls the state or the opening degree of the second water supply control valve 25 based on data sensed by the temperature sensor 34 installed in the main body 31 of the steam generating device 30. The control of the supply of water sensed by the temperature sensor 34 is performed such that the supply of water is decreased or stopped when the temperature of the main body 31 is excessively lowered and is increased when the temperature of the main body 31 is excessively raised. When the steam generating device 30 is applied to the washing machine as in the present invention, the above control unit is installed integrally with another control unit for controlling the overall operation of the washing machine, and when the steam generating device 30 is used separately from the washing machine, the above control unit is separately installed to control only the operation of the steam generating device 30.

The steam generating device 30 further includes an automatic temperature switch 41 and a fuse 42, installed on the outer surface of the main body 31, serving as preliminary overheating prevention devices for controlling power supplied to the heater 33 to prevent the overheating of the heater 33 when the supply of water to the steam generating device 30 is stopped or the temperature of the heater 33 is excessively raised due to the malfunction of the temperature sensor 34. FIG. 5 is a circuit diagram illustrating the connection of the heater 33, the automatic temperature switch 41, the fuse 42, and a power source 43.

The automatic temperature switch 41 is used when the temperature sensor 34 malfunctions so that it is difficult to control the temperature of the heater 33, and serves to cut off power applied to the heater 33 when the temperature of the main body 31 is increased more than a first predetermined temperature range (for example, 170˜180° C.) higher than a range controlled by the temperature sensor 34 and to apply power to the heater 33 when the temperature of the main body 31 is decreased again. The automatic temperature switch 41 employs a conventional thermostat.

The fuse 42 is used when the automatic temperature switch 41 malfunctions, and is cut when the temperature of the main body 31 is increased more than a second predetermined temperature (for example, 220° C.) higher than the first predetermined temperature range, thereby completely cutting off the supply of power to the heater 33. The fuse 42 completely cuts off the supply of power to the heater 33 when the temperature of the main body 31 is excessively increased, thus preventing peripheral parts of the washing machine from being damaged by heat and protecting the washing machine from danger of a fire.

In order to prevent generation of scales on the inner surface of the steam supply channel 32 due to calcium or magnesium contained in water passing through the steam supply channel 32, as shown in FIG. 6, a noncohesive coating layer 50 is formed on the inner surface of the steam supply channel 32. The noncohesive coating layer 50 is formed by coating the inner surface of the steam supply channel 32 with fluorine ceramic having excellent noncohesiveness and heat-resistance, or Teflon. The noncohesive coating layer 50 smoothes the inner surface of the steam supply channel 32 and increases the noncohesiveness of the inner surface of the steam supply channel 32, thereby preventing deposition of foreign substances on the inner surface of the steam supply channel 32, thus preventing the generation of scales.

Hereinafter, the overall operation of the washing machine, to which the above steam generating device is applied, will be described.

When the washing operation of the washing machine is performed under the condition that laundry is inserted into the rotary drum 20 and the detergent is introduced into the detergent supply device 18, the first water supply control valve 22 is opened by the control motion of the control unit of the washing machine so that water is supplied to the detergent supply device 18. The detergent in the detergent supply device 18 is supplied to the tub 11 under the condition that the detergent is dissolved in the water supplied to the tub 11. After a designated quantity of washing water is supplied to the inside of the tub 11, the first water supply control valve 22 is closed so that the supply of the washing water to the first water supply pipe 21 is stopped.

When a user selects a washing operation using steam of a high temperature, power is applied to the heater 33 of the steam supply channel 32 by the control motion of the control unit so that the main body 31 of the steam generating device 30 is heated. Here, water is not supplied to the steam generating device 30 for a designated time (for example, 30 seconds) so that the main body 31 is pre-heated.

When it is determined that the main body 31 of the steam generating device 30 is sufficiently pre-heated by the temperature sensor 34, the control unit opens the second water supply control valve 25 so that the water is supplied to the steam generating device 30 to generate steam. Since the main body 31 is pre-heated, the steam of a high temperature is generated just after the water is supplied to the steam generating device 30, and is supplied to the tub 11 through the steam supply pipe 26. Therefore, the washing water in the tub 11 is rapidly heated by the steam of the high temperature. The heating of the washing water using the steam is continuously performed until the temperature of the washing water reaches a predetermined washing temperature.

After the washing water is heated to the predetermined washing temperature, the second water supply control valve 25 is closed and the operation of the heater 33 is stopped so that the supply of the steam is stopped, and the rotary drum 12 is rotated at a low temperature by the motion of the motor 15, thereby performing the washing operation of the washing machine. After the washing operation is completed, a rinsing operation, in which the dehydration and the water supply are repeated, is performed.

The discharge of the washing water from the tub 11 is performed by opening the drainage valve 19 b and operating the drainage pump 19 c. A final dehydrating operation after the rinsing operation is performed by operating the drainage pump 19 c under the drainage valve 19 b is opened and rotating the rotary drum 12 at a high speed for a designated time.

As apparent from the above description, the present invention provides a steam generating device, in which water is heated to generate steam of a high temperature just after the water is supplied to a steam supply channel so that the steam is supplied to a tub in a short time, and the operating time of a heater is shortened compared to a conventional steam generating device so that the consumption of energy is decreased, and a washing machine having the same.

The steam generating device of the present invention does not require a pressure container, a water level sensor, and a pressure valve, thus having a simple configuration compared to the conventional steam generating device, thereby greatly reducing the volume and the production costs thereof.

The steam generating device of the present invention is provided with an outlet opened at all times, thereby preventing danger in use due to the increase in pressure thereof.

The steam generating device of the present invention cuts off power applied to a heater using an automatic temperature switch or a fuse when the temperature of the heater is excessively raised due to the stoppage of the supply of water to the steam generating device or the malfunction of a temperature sensor, thereby preventing the overheating thereof and allowing the washing machine to be stably used.

The steam generating device of the present invention includes a noncohesive coating layer formed on the inner surface of the steam supply channel, thereby preventing generation of scales in the steam supply channel.

Although exemplary embodiments of the invention have been shown and described, it will be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents. 

1. A steam generating device comprising: a main body provided with a steam supply channel formed therein; a heater buried in the main body for heating the main body to heat water flowing along the steam supply channel; and a water supply control valve installed at an inlet of the steam supply channel.
 2. The steam generating device as set forth in claim 1, wherein the main body is a metal mold manufactured such that a pipe for forming the steam supply channel and the heater are buried in the main body.
 3. The steam generating device as set forth in claim 1, wherein the steam supply channel is formed in a longitudinal direction of the main body, and the heater buried in the main body is separated from the steam supply channel and extended in the longitudinal direction of the main body.
 4. The steam generating device as set forth in claim 1, wherein the diameter of an outlet of the steam supply channel is smaller than the diameter of an inlet of the steam supply channel.
 5. The steam generating device as set forth in claim 1, wherein a spiral coil member for delaying the flow of water is installed in the steam supply channel.
 6. The steam generating device as set forth in claim 1, further comprising an overheating prevention device for controlling power applied to the heater when the heater is overheated.
 7. The steam generating device as set forth in claim 6, wherein the overheating prevention device includes: a temperature sensor for sensing the temperature of the main body; and an automatic temperature switch for cutting off the power applied to the heater when the temperature of the main body is raised more than a first predetermined temperature.
 8. The steam generating device as set forth in claim 7, wherein the overheating prevention device further includes a fuse for cutting off the power applied to the heater when the temperature of the main body is raised more than a second predetermined temperature higher than the first predetermined temperature.
 9. The steam generating device as set forth in claim 1, wherein the main body is a metal mold manufactured such that a core for forming the steam supply channel and the heater are buried in the main body.
 10. The steam generating device as set forth in claim 1, wherein an outlet of the steam supply channel is opened at all times.
 11. The steam generating device as set forth in claim 1, further comprising a noncohesive coating layer formed on the inner surface of the steam supply channel for preventing the generation of scales in the steam supply channel.
 12. A washing machine having a steam generating device for supplying steam to the inside of a tub, said steam generating device comprising: a main body provided with a steam supply channel formed therein; a heater buried in the main body for heating the main body to heat water flowing along the steam supply channel; and a water supply control valve installed at an inlet of the steam supply channel.
 13. The washing machine as set forth in claim 12, wherein the main body is a metal mold manufactured such that a pipe for forming the steam supply channel and the heater are buried in the main body.
 14. The washing machine as set forth in claim 12, wherein the steam supply channel is formed in a longitudinal direction of the main body, and the heater buried in the main body is separated from the steam supply channel and extended in the longitudinal direction of the main body.
 15. The washing machine as set forth in claim 12, wherein the inner diameter of an outlet of the steam supply channel is smaller than the inner diameter of an inlet of the steam supply channel.
 16. The washing machine as set forth in claim 12, wherein a spiral coil member for delaying the flow of water is installed in the steam supply channel.
 17. The washing machine as set forth in claim 12, further comprising an overheating prevention device for controlling power applied to the heater when the heater is overheated.
 18. The washing machine as set forth in claim 17, wherein the overheating prevention device includes: a temperature sensor for sensing the temperature of the main body; and an automatic temperature switch for cutting off the power applied to the heater when the temperature of the main body is raised more than a first predetermined temperature.
 19. The washing machine as set forth in claim 18, wherein the overheating prevention device further includes a fuse for cutting off the power applied to the heater when the temperature of the main body is raised more than a second predetermined temperature higher than the first predetermined temperature.
 20. The washing machine as set forth in claim 12, further comprising a noncohesive coating layer formed on the inner surface of the steam supply channel for preventing the generation of scales in the steam supply channel. 